Grinding mill



\ J. s. BARTLEY GRINDING MILL Origihazl Filed Nov. 14, 1919 INVENTOR. J6 BARTLE 4 BY 9 W I A TTORNE Y.

Patented Feb. 10, 1925.

u T-En, s'rArE-s JOSEPH s. BARTLEY, or nnnvnn, oononnno.

GRINDING MILL;

Application filed November 1 4, 1919, Serial No. 338,019. Renewed May14, 1924.

To all whom it may concern:

Be itknown that I, Josnrn S. Banner, a citizen of the United States,-residing at Denver, in the county of Denver and State of Colorado, haveinvented certain new and useful Improvements in Grinding Mills, of

" which the following is a specification.

This invention relates to grinding mills of the type commonly known asrod mills in which a mass of loose rods have atumbling motion in arotating drum.

The primary object of the invention istoprovide in a .mill of the abovedescribed character, a plurality of loose grinding 'rolls which arelongitudinally fluted to provide rounded teeth or ridges which altematewith furrowsordepressions of greater width.

A mass of rolls of this form loosely placed within the cylinder willmesh with each other and with the lifting or tumbling. ribs usuallyprovidedon the. inside of the rotating cylinder," thereby increasing thep the line 2.2, Figure 1.

Referring to the drawings by numerals, 2 designates the grinding drum ofthe mill which is mounted for rotation about a horizontal axis, upon twopedestals 3. i The drum is composed of a cylindrical shell 4 whichisclosed at its ends by heads 5 and 6 provided with central hollowtrunnions 7 and 8, resting in pillow boxes 10' on, the pedestals 3.

The trunnions 7 carries a scoop 12 for feeding ore pulp or othermaterial in liquid into the cylinder-and the opposite trunnion 8 servesfor the discharge of the disintegrated product which risesin the liquidand is displaced by the constant inflow of fresh material.

. Bolted upon the interior surface of the shell are equidistant liftingribs 13 of rounded section which in the operation of the mill serve tolift the grinding bodies and the material under treatmentfrom the bottomof I thei'otating cylinder to produce a tumbling and cascading movementthereof.

- tering through The grinding bodies of the present invention consist ofrolls 14: which are fluted to provide longitudinal-teeth or ridges l5alternating with depressions or furrows 16 of greated width.

equally spaced around the tumbling rolls at an angle of 120 degrees,producing a substantially triangular formation of the tumbling rolls.

The rolls are preferably madehollow for the reception of rods 17 whichaugment their grinding action and increase their weight.

The rods extending loosely in the bores of the rolls, permit of thepassage of material around them and thus cooperate with v the rolls toincrease their grinding capacity.

. The rods furthermore serve as a filler which is readily removed whenthe roll is worn out, and placed in another roll, thereby preventing thewaste of metal which would be unavoidable in case the rolls were solid.

A mass of the rolls laced loosely in a rotating grinding cylin er, havea triturating act1on uponthe material constantly-enthe trunnion 7 at thefeed end of the same, by their tumbling and rotating movements.

The outermost rolls of the mass congre ating in the bottom portion ofthe cylin er, mesh with the lifting ribs .011 the inner circumference ofthe same and all the rolls contained in the mass intennesh with eachother as closely as the presence of the material under treatmentpermits.

-' During rotation of the cylinder in the direction of the arrow A,Figure 2, the several rolls are thus lifted to a point of release bygravitation and, togetherwith material carried in their furrows, arecaused to drop successively to the bottomof the drum;- The falling rollsmeshing with those adjoining, impart a rotary motion thereto which isagain transmitted to the next following rolls and so on mass. I J

The rotary movement of the cylinder thus produces a continuous cascadingmovement of rotating bodies and interflowing ore pulp,

through the entire that the fu rows] in the rolls serve as carriers tolift the material accumulating ii. the bottom portion of the cylinder,and that the peculiar form of the rolls permits of their approachingeach other sufficiently near to .have a direct crushing action upon allthe ore between them.

A great advantage is thus obtained over existing machines in which thegrinding bodies are of circular section and contact with each other andwith the lifting ribs only along tangent lines.

What I claim and desire to secure by Letters-Patent is:

'1'; *In a mill of the class described, the combination of a rotatinggrinding drum rovided at its inner surface with relatively argelongitudinal lifting ribs, and a plurahty of loose tumbling rollsprovided with relatively large ribs disposed in substantially trian ularformation and said tumbling rolls eing adapted'to engage the liftingribs and mesh with one another whereby they will be rotated 'by therotary move ment of the drum.

2. In a mill of. the class described, the combination of a rotatinggrinding drum provided at its inner surface with relatively largelongitudinal lifting ribs, presenting rounded engaging surfaces, and aplurality of loose tumbling rolls filling approximately one-half of thedrum and. provided with relatively large ribs disposed in substantiallytriangular formation and presenting rounded projecting surfaces andhaving intervening concave surfaces.

3. In combination, a grinding 1nill, and a plurality of freely tumblingelongated bars, certain of said bars having longitudinally extendingdomes or convex portions and certaing of said bars having longitudinallyex tending concaved portions to cooperate with said domes or convexportions, the radii of said convex and concave portions beingsubstantially equal.

In testimony whereof I have 'afiixed my signature.

JOSEPH S. .BARTLEY.

